Kingdom Protoctista Hogg, 1860
   Phylum Bacillariophyta Engl. & Gilg (1919) - diatoms see [unranked] Diatomea Kütz. (1844)
     Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics
       Subclass Rhizosoleniophycidae Round & R.M. Crawford (1990)
         Order Rhizosoleniales P.C.Silva (1962)
           Family Rhizosoleniaceae De Toni (1890)
             1 Genus Rhizosolenia Brightw. (1858)
             2 Genus Guinardia H. Perag. (1892)
             3 Genus Dactyliosolen Castrac. (1886)
             4 Genus Pyxilla Grev. (1865)
             5 Genus Gladius Forti & Schulz (1932)
             6 Genus Gyrodiscus Witt (1886)
             7 Genus Mastogonia Ehrenb. (1844)
             8 Genus Pyrgupyxis Hendey (1969)